My point is that even though "TBPWM" does *not* have a Roud number (any more than does "Smoke Gets in Your Eyes," which I happen to prefer) there is nothing in theory to keep either one of them from getting one in the far future.

'Shoals of Herring' has a Roud number, as does Jimmy Rodgers' 'Away Out on the Mountain' - though NOT (apparently) because it was sung by the late great Jane Turriff, as featured on YouTube (what is it with Mudcatters that persist with U-Tube?):

http://www.youtube.com/watch?v=Sn2UTXDIDCA

I don't get this, personally. The persistence of 'Traditional' into the modern age isn't something I'm convinced by and smacks of a pure-blood authenticity that sticks in my craw - and is genuinely the point I usually part company with Folkies and go and listen to something genuinely traditional like The Fall or Yes. No doubt 'The Revealing Science of God' or 'Jaw Bone and the Air Rifle' could have Round numbers too if they were to be covered by a 100% genuine bona-fide traditional singer.

A weird world...